If I weren't interested in football I wouldn't have minded watching the film on Channel Two yesterday evening.
The "Type 1 Conditional" form is:
If I am not interested in football, I won't mind watching the film on Channel Two yesterday evening. (Note that the future "won't" and the past "yesterday" are contradictory, and this sentence does not make any sense.)
The so-called "Type 2 Conditional" form has the simple past in the "if" clause,
except for the verb "to be", which in the Type 2 Conditional form is always "were", not "was".
So the Type 2 Conditional form of this would be:
If I weren't interested in football, I wouldn't mind watching the film on Channel Two yesterday evening. (Note: not "wasn't", because "to be" is an exception. And "wouldn't minded" is not correct.) But Type 2 is also a sort of future - a hypothetical future, let's say. So this sentence does not make any sense either because of the "yesterday".
The Type 3 Conditional form would be:
If I hadn't been interested in football, I wouldn't have minded watching the film on Channel Two yesterday evening. ("have minded" makes it past, so this sentence is OK with "yesterday".) This sentence says, "I did mind watching the film".
The example sentence is, as you have seen, neither Type 2 nor Type 3. It is an exceptional case, which is also correct. We can call it Type 4 if you like!
![Smile [:)]](/emoticons/emotion-1.gif)
In fact, we can list at least five types, although most books list only the three most common.
1: IF present, will ...
2: IF past, would ...
3: IF past perfect, would have ...
4: IF past, would have ... (IF Type2 - Type 3 mixed)
5: IF past perfect, would ... (IF Type 3 - Type 2 mixed)
Type 4:
If I spoke Japanese, I would have translated the documents for you.
If I were smart, I would have bought that book when it was on sale.
And the example that started this thread:
If I weren't interested in football I wouldn't have minded watching the film on Channel Two yesterday evening.
Type 5.
If George had taken those math courses last year, he would now be much farther along in earning his degree.
If Marge had won the prize money, she would already be spending it on new clothes.
If he had seen the film, he would know what we're talking about.
Hope this helped you more than it complicated your life!
See http://www.englishpage.com/conditional/mixedconditional.html for a variety of examples, some of which were the models for mine above.